Evaluation of the clinical impact of CEUS in the abdominal aneurysm treatment

Abstract

Endovascular aneurysm repair (EVAR) is an effective alternative treatment to open repair of abdominal aortic aneurysm and the number of EVAR procedures carried out worldwide is continuously growing. Incomplete exclusion of the aneurysm sac from the circulation, defined as endoleak, is the most frequent complication after EVAR occurring in 10% to 45% of cases, and it can be associated with aneurysm enlargement and possible rupture. Despite its notable advantages, ultrasonography has not yet achieved reference standard status in the EVAR follow-up because of low diagnostic specificity and sensitivity. Recent studies on ultrasound examinations performed without echo-contrast agents reported sensitivity rates ranging from 43% to 97%, such wide differences suggesting that it does not guarantee the necessary reliability. Therefore, to date computed tomography angiography (CTA) is the preferred imaging modality to follow-up patients after EVAR. However, CTA surveillance carries the risks associated with radiation and contrast media exposure. Magnetic resonance angiography (MRA) and contrast-enhanced ultrasonography (CEUS) have been shown in some studies a better accuracy than CTA. However, there is no consensus with regard of optimal work-up with diagnostic imaging modalities in surveillance after EVAR. The accuracy of current imaging modalities in the detection and characterization of endoleaks in aortic endografts, focusing especially on the accuracy of CEUS with the use of second generation contrast agent have been presented. The advantages, the limitations of CEUS in comparison with CTA and MRA, will be discussed. In conclusion, CDUS is inadequate for the surveillance of patients after EVAR. The results of the present study showed that CEUS is an effective tool for surveillance after EVAR because it is fast, cheaper but equally accurate compared to CTA or MRA, can be repeated frequently even at bedside, also in the immediate postoperative period. The limitations of CEUS are mainly due to its operator dependence and patients’ habitus. Based on these findings, we do believe that CEUS is a valuable adjunctive imaging modality to CTA and MRA in detecting endoleaks after EVAR.